diff --git a/crates/oxc_isolated_declarations/src/class.rs b/crates/oxc_isolated_declarations/src/class.rs
index 5dfab8a13..d16b35439 100644
--- a/crates/oxc_isolated_declarations/src/class.rs
+++ b/crates/oxc_isolated_declarations/src/class.rs
@@ -117,8 +117,8 @@ impl<'a> IsolatedDeclarations<'a> {
             FunctionType::TSEmptyBodyFunctionExpression,
             function.span,
             self.ast.copy(&function.id),
-            function.generator,
-            function.r#async,
+            false,
+            false,
             false,
             self.ast.copy(&function.type_parameters),
             self.ast.copy(&function.this_param),
diff --git a/crates/oxc_isolated_declarations/tests/fixtures/async-function.ts b/crates/oxc_isolated_declarations/tests/fixtures/async-function.ts
index 3927f10d1..b1a8d9a6a 100644
--- a/crates/oxc_isolated_declarations/tests/fixtures/async-function.ts
+++ b/crates/oxc_isolated_declarations/tests/fixtures/async-function.ts
@@ -5,6 +5,12 @@ const asyncFunctionGoo2 = async (): Promise<number> => {
 }
 
 
+class AsyncClassGood {
+  async method(): number {
+    return 42;
+  }
+}
+
 // Need to explicit return type for async functions
 // Incorrect
 async function asyncFunction() {
@@ -13,4 +19,10 @@ async function asyncFunction() {
 
 const asyncFunction2 = async () => {
   return "Hello, World!";
+}
+
+class AsyncClassBad {
+  async method() {
+    return 42;
+  }
 }
\ No newline at end of file
diff --git a/crates/oxc_isolated_declarations/tests/fixtures/generator.ts b/crates/oxc_isolated_declarations/tests/fixtures/generator.ts
index c09739a26..2666ea029 100644
--- a/crates/oxc_isolated_declarations/tests/fixtures/generator.ts
+++ b/crates/oxc_isolated_declarations/tests/fixtures/generator.ts
@@ -1,10 +1,25 @@
 // Correct
 function *generatorGood(): Generator<number> {}
 
+class GeneratorClassGood {
+  *method(): Generator<number> {
+    yield 50;
+    return 42;
+  }
+}
+
+
 
 // Need to explicit return type for async functions
 // Incorrect
-function *generatorGoodBad() {
+function *generatorBad() {
   yield 50;
   return 42;
+}
+
+class GeneratorClassBad {
+  *method() {
+    yield 50;
+    return 42;
+  }
 }
\ No newline at end of file
diff --git a/crates/oxc_isolated_declarations/tests/snapshots/async-function.snap b/crates/oxc_isolated_declarations/tests/snapshots/async-function.snap
index 3af230361..7e275fdae 100644
--- a/crates/oxc_isolated_declarations/tests/snapshots/async-function.snap
+++ b/crates/oxc_isolated_declarations/tests/snapshots/async-function.snap
@@ -6,26 +6,41 @@ input_file: crates/oxc_isolated_declarations/tests/fixtures/async-function.ts
 
 declare function asyncFunctionGood(): Promise<number>;
 declare const asyncFunctionGoo2: () => Promise<number>;
+declare class AsyncClassGood {
+	method(): number;
+}
 declare function asyncFunction();
 declare const asyncFunction2: unknown;
+declare class AsyncClassBad {
+	method();
+}
 
 
 ==================== Errors ====================
 
   x TS9007: Function must have an explicit return type annotation with
   | --isolatedDeclarations.
-    ,-[10:16]
-  9 | // Incorrect
- 10 | async function asyncFunction() {
+    ,-[16:16]
+ 15 | // Incorrect
+ 16 | async function asyncFunction() {
     :                ^^^^^^^^^^^^^
- 11 |   return 42;
+ 17 |   return 42;
     `----
 
   x TS9007: Function must have an explicit return type annotation with
   | --isolatedDeclarations.
-    ,-[14:30]
- 13 | 
- 14 | const asyncFunction2 = async () => {
+    ,-[20:30]
+ 19 | 
+ 20 | const asyncFunction2 = async () => {
     :                              ^^^^^^^
- 15 |   return "Hello, World!";
+ 21 |   return "Hello, World!";
+    `----
+
+  x TS9008: Method must have an explicit return type annotation with
+  | --isolatedDeclarations.
+    ,-[25:9]
+ 24 | class AsyncClassBad {
+ 25 |   async method() {
+    :         ^^^^^^
+ 26 |     return 42;
     `----
diff --git a/crates/oxc_isolated_declarations/tests/snapshots/generator.snap b/crates/oxc_isolated_declarations/tests/snapshots/generator.snap
index b72acbc6c..8a0dd9ed5 100644
--- a/crates/oxc_isolated_declarations/tests/snapshots/generator.snap
+++ b/crates/oxc_isolated_declarations/tests/snapshots/generator.snap
@@ -5,16 +5,31 @@ input_file: crates/oxc_isolated_declarations/tests/fixtures/generator.ts
 ==================== .D.TS ====================
 
 declare function generatorGood(): Generator<number>;
-declare function generatorGoodBad();
+declare class GeneratorClassGood {
+	method(): Generator<number>;
+}
+declare function generatorBad();
+declare class GeneratorClassBad {
+	method();
+}
 
 
 ==================== Errors ====================
 
   x TS9007: Function must have an explicit return type annotation with
   | --isolatedDeclarations.
-   ,-[7:11]
- 6 | // Incorrect
- 7 | function *generatorGoodBad() {
-   :           ^^^^^^^^^^^^^^^^
- 8 |   yield 50;
-   `----
+    ,-[15:11]
+ 14 | // Incorrect
+ 15 | function *generatorBad() {
+    :           ^^^^^^^^^^^^
+ 16 |   yield 50;
+    `----
+
+  x TS9008: Method must have an explicit return type annotation with
+  | --isolatedDeclarations.
+    ,-[21:4]
+ 20 | class GeneratorClassBad {
+ 21 |   *method() {
+    :    ^^^^^^
+ 22 |     yield 50;
+    `----